This invention relates generally to valves usable to deliver water from housing or building plumbing lines. More particularly, it concerns improvements to such valves, simplifying their construction, and enhancing their performance.
There is need in such valves for improvements associated with blocking or checking back flow where reverse flow pressure may build-up. Also, there is need in such valves for disposing of build-up back flow pressure, as during checking or blocking of such back flow to the building plumbing. Such back flow, if unchecked, could contaminate water in that plumbing.
U.S. Pat. No. 5,752,542 to Hoeptner discloses an improved valve constructed to meet the above needs. That valve incorporates the following:
a) an outer tubular member having a first flow port,
b) an inner member having closure means thereon to close the port in relatively axially advanced position of the inner member, and to open the port in relatively axially retracted position of the inner member,
c) control means to control relative movement of the inner member between those positions,
d) an axially movable check valve positioned about the axis of the inner member to pass fluid flow from the port and to drain flow space defined between the members, and to block reverse fluid flow from that space and through the first port, in the inner member relatively retracted position, and
e) a second port to pass fluid from that space in relatively retracted position of the inner member, thereby to relieve pressure of the fluid in the space.
There is further need to control pressurized fluid for escape from the interior of the valve at times when the check valve is positioned to block reverse fluid flow as referred to, and at other times to block such escape.
It is a major object of the invention to provide an improved, compact, simple, highly effective valve assembly meeting the above need. Basically, the assembly comprises:
a) an elongated hollow valve body having an inlet and an outlet for fluid flow,
b) a valve in said body to control said flow,
c) an elongated hollow stem movable in the body to open and close the valve,
d) packing extending between portions of the stem and body, in spaced relation to the valve,
e) a side drain port in and movable by the stem between a first position in which the port is blanked by the packing, and a second position in which the port is exposed to fluid in the body outside the stem, to pass such fluid into the stem for drainage.
As will appear, the valve in the body to control such flow typically includes a back flow controlling check valve, which may be carried by the stem, in axially spaced relation to the packing and side drain port,
It is another object to configure the valve to be open when the port is in said first position, and the valve is closed when the port is in said second position.
Another object includes provision of a handle attached to said stem externally of said body to rotate the stem in the body, the side drain port located between the handle and valve. The stem may have screw thread attachment to the body to effect endwise movement of the stem relative to the body when the handle is rotated, thereby to carry the port between said first and second positions.
A further object is to provide an elongated tubular body in which the stem and valve are received, that body having a side outlet, and the valve comprising a check valve engagable with and disengagable from a bore in the tubular body, in spaced relation to the body side outlet.
A yet further object includes provision of a back siphonage controlling check valve assembly connected in series with the body side outlet; and in which said additional check valve assembly may have a side discharge port via which fluid can escape under excess pressure conditions.
An additional object includes provision of a deflector associated with a diaphragm controlled side discharge port to deflect fluid escaping under such excess pressure conditions.